Design of a Low Vibration and Low Acoustic Noise Seek Control method for Hard Disk Drives

In Hard Disk Drives, there are two seek modes. One is a short distance seek mode, the other is a long distance seek mode. There is not saturaliton in the short distance seek mode, so many methods were proposed to realize a low acoustic noise and low vibration seek. However, in order to realize a low acoustic noise seek in Hard Disk Drives, the long distance seek mode is very important. So, a new method for the long distance seek is proposed in this paper. In conventional methods, a reference velocity curve is used. This reference velocity curve can be considered a switching line in the phase plane. In the proposed method for a long distance seek, the sliding mode controller with a frequency-shaped switching line is designed for a feedforward controller. The advantage of this method is a hign frequency ingredient in the feedforward input can be eliminated by setting the frequency-shaped switching line. The validity of the proposed method was confirmed by numerical and experimental results using a miniature 2.5-inch Hard Disk Drive.